Tjernlund CPC-2 Constant Pressure Controller (Discontinued) 8504091 Rev A 03/01 - Manual (Page 11)

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INITIAL SYSTEM POWER UP AND SET UP OF CPC-2 CONTROLLED VENTING SYSTEM
IMPORTANT: CPC-2 can be reset to previously saved programmed settings by by momentarily turning power “off” then “on” again.
1. Verify that all of the components are installed and the system is wired correctly.
2. Interlock the appliances per the appropriate diagram in the appliance wiring section.
3. Shut off power to each appliance using service disconnect switch(es). Wire complete CPC-2 controlled system per appropriate
diagrams. Establish power to the CPC-2 by turning the power switch on (#28 Circuit Board Call Outs). Establish power to the
VFD by switching on breaker and/or disconnect. In turning the power on to the drive and the controller, the venter and the
expansion boards, if used, will also have power.
4. With the secondary fan prover, i.e. PSA-1 installed, wired and connected to sampling tube, adjust the prover set screw counter
clockwise until it stops. Do not force the setting past the stop.
5. Close all doors and manually operated openings to the mechanical room. Turn on any air removing equipment such as ventilation
fans and other heating appliances not connected to this system.
CONFIRMING PROPER IMPELLER ROTATION
Reference the motor amp draw of the venter model you are installing. This information can be found in the venter installation instruc-
tions or on the venter nameplate.
6. Depress DSPL key on the VFD until "IOUT" is lit.
7. Unlock the keypad of the CPC-2 by depressing SAVE SETTING / SETUP/ SAVE SETTING.
8. Depress the VENTER ONLY button on the CPC-2 and then increase the venter speed by depressing the INCREASE button.
As you increase the venter speed take note of the venter amp draw displayed on the VFD. The actual amp draw should not
exceed the nameplate amp draw prior to reaching 100% on the display of the CPC-2. If you reach or exceed the venter amp
rating prior to reaching 100% venter speed, disrupt power to the VFD and switch any two leads to the M1, M2 or M3 terminals
of the VFD terminal strip. Reestablish power to the VFD and repeat this procedure to confirm that the actual motor amp draw is
within the specifications for the venter model installed.
NOTE: Inrush amps on initial start-up may exceed nameplate ratings.
9. Turn off the Venter Only option by depressing the VENTER ONLY button.
BALANCING DRAFT OF INDIVIDUAL APPLIANCES
10. Close all balancing dampers and secure in place. The CPC-2 should be in the Automatic mode. The default vent pressure should
read: (V SET -0.15 inWC or V SET 37.4 Pa). Verify that all heating appliance disconnect switch(es) are in the “off” position.
11. Turn appliance disconnect switch “on” and initiate a call for heat on the appliance that is furthest from the venter (or the appliance
that is hardest to vent). The call for heat should activate the venter. When the vent pressure set point is reached the burner should
fire. Open the balancing damper until (-0.03" W.C. or 7.5 Pa) is observed as the draft pressure for the appliance. Measure draft at
the point referenced by the heating appliance manufacturer. If the appliance has a vent damper verify that it has opened.
WARNING: Never allow an appliance to fire if excessive over or under draft pressure is present. If needed, contact the appliance
manufacturer for the light off and operating draft pressure range. Most appliances will safely operate with draft levels between
(-0.01" to -0.06" W.C. or 2.5 to 15 Pa).
12. Turn appliance disconnect switch “on” and initiate a call for heat on the appliance that is next furthest from the venter (or the appli-
ance that is next hardest to vent). Open the balancing damper until (-0.03" W.C. or 7.5 Pa) is measured as the draft pressure for
this appliance. Monitor the draft and adjust the balancing damper as necessary until a steady draft of (-0.03" W.C. or 7.5 Pa) is
maintained.
13. Repeat step 12 for the remaining appliances until they all have had the draft pressure set and are at steady state conditions.
WARNING: An adjustment to any one balancing damper will effect the shared manifold pressure to all. Make sure to keep check-
ing the draft pressure to all of the appliances. Do not allow appliances to shut off during this process. You are setting the system
for the maximum load or demand. All of the appliances tied to this system must be on, running, and at steady state conditions
during this process.
14. If the venter speed reaches 100% before all of the appliances have been fired at steady state conditions, you may need to consid-
er a lower vent pressure set point on the CPC-2 or slightly lower (less draft) draft pressure at each appliance. WARNING: Never
settle for a light off or draft pressure that is outside of the range specified by the appliance manufacturer.